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[Isoproterenol infusion stress two-dimensional echocardiography in detecting coronary artery disease]
Insights
Isoproterenol (ISP) stress echocardiography effectively detects left ventricular (LV) wall motion abnormalities for diagnosing coronary artery disease (CAD). This method overcomes limitations of exercise echocardiography, showing superior specificity compared to stress electrocardiography.
Area of Science:
- Cardiology
- Diagnostic Imaging
- Non-invasive Cardiac Assessment
Context:
- Dynamic exercise 2-D echocardiography is limited in patients with reduced physical capacity or difficulty with recordings due to movement/hyperventilation.
- Coronary artery disease (CAD) diagnosis requires reliable non-invasive methods.
- Assessing left ventricular (LV) wall motion abnormalities is crucial for CAD detection.
Purpose:
- To evaluate the efficacy of isoproterenol (ISP) infusion stress 2-D echocardiography in detecting transient LV asynergy for CAD diagnosis.
- To compare the diagnostic performance of ISP stress 2-D echocardiography with exercise echocardiography and electrocardiography.
Summary:
- Isoproterenol (ISP) stress 2-D echocardiography demonstrated high feasibility (82.2% of segments) and safety, with no hazardous arrhythmias or severe anginal pain.
- The method successfully detected or exaggerated LV wall motion abnormalities in patients with old myocardial infarction (OMI) and angina pectoris (AP).
- Normal LV wall motion was observed during ISP infusion in subjects without CAD, showing higher specificity compared to ISP stress electrocardiography.
Impact:
- ISP stress 2-D echocardiography offers a valuable alternative for CAD diagnosis, especially in patients unable to perform exercise tests.
- This technique enhances diagnostic accuracy by mitigating recording difficulties associated with exercise.
- The findings support ISP stress 2-D echocardiography as a safe and useful tool for identifying coronary artery stenosis.
Abstract:
Dynamic exercise two-dimensional (2-D) echocardiography has been utilized as a valuable method in the diagnosis of coronary artery disease (CAD). However, there are some limitations in this technique including inability to apply for patients whose physical capacity is limited. Moreover, appropriate echocardiographic recordings are frequently difficult because of bodily movements and/or hyperventilation during exercise. In order to overcome these limitations, we examined whether isoproterenol (ISP) infusion stress 2-D echocardiography could detect transient LV asynergy or not. The subjects consisted of 19 cases with angina pectoris (AP), 16 with old myocardial infarction (OMI), nine with atypical chest pain syndrome and six with miscellaneous heart disease. ISP stress test was performed prospectively as follows: ISP was infused at a rate of 0.02 microgram/kg/min until anginal pain occurred or significant ST depression (elevation) developed. Real time 2-D echocardiograms were obtained in the short-axis or apical RAO views of the LV before and every one minute during ISP infusion test. Coronary artery stenosis was considered to be present if the narrowing was 50% or more in the luminal diameter. The results were as follows: Adequate echocardiographic recordings were obtained in 86.1% of LV segments at rest, and in 82.2% during ISP infusion. Echocardiographic recordings during ISP infusion were feasible in almost all cases. LV wall motion abnormalities were detected in 12 (86%) of the 14 subjects with OMI and two (29%) of the seven subjects with AP at rest, while induced or exaggerated in nine (64%) of the 14 subjects with OMI and all of the 7 subjects with AP during ISP infusion. On the other hand, LV wall motion remained entirely normal during ISP infusion in 11 (92%) of the 12 subjects without CAD. In 4 (40%) of these 10 subjects without CAD, electrocardiographic judgements were positive in the ISP stress test. None had hazardous arrhythmias or severe anginal pain. ISP infusion stress 2-D echocardiography possessed feasibility of detecting LV wall motion abnormalities because this method could exclude difficulty of recordings due to bodily movements and/or hyperventilation seen in exercise echocardiography. Compared with ISP stress electrocardiography, 2-D echocardiography seemed to be superior with respect to the specificity in detecting CAD. In conclusion, ISP stress echocardiography is a safe and useful method in the diagnosis of CAD.